Sorry, I just checked a situation and can not confirm your sayings. Here is my log: 
D:\Work\PerlScripts\utl>perl -MO=Deparse -we "$x=[];for(@$x){}"
$x = [];
foreach $_ (@$x) {
    ();
}
-e syntax OK

D:\Work\PerlScripts\utl>perl -MO=Deparse -we "$x=[];for(;;){}"
Name "main::x" used only once: possible typo at -e line 1.
$x = [];
for (;;) {
    ();
}
-e syntax OK

D:\Work\PerlScripts\utl>perl -MO=Deparse -we "$x=[];for($i=0;$i<=$#x;$
+i++){}"
$x = [];
for ($i = 0; $i <= $#x; ++$i) {
    ();
}
-e syntax OK

[download]
This is probably version-dependent (which perl version you use?) and with less probablilty $^O-dependent (what is $^O in your case?)

I think we'll find common denominator soon.

update: after I saw your update I understood more and now I think we found that commond denominator that I've just mentioned. Thanks.

In reply to Re: Re: Is for(@$array_ref) construct optimized? YES! by Weasel
in thread Is for(@$array_ref) construct optimized? YES! by Weasel

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